| Abstract | | Behavioral and neuroimaging studies provide converging evidence for harmonic
expectation in the human brain. Few studies, however, have addressed the questions of a) what
harmonies humans expect given specific melodies, and b) how harmonic expectation relates to
the experience of affect in music. The present study addresses these two questions. The first
experiment uses a reaction time paradigm in which subjects heard series of five-chord
progressions. As each chord played, subjects responded as to whether the melodic pitch (defined
as the highest pitch of each chord) went up, down, or stayed constant compared to the melodic
pitch before it. Three types of chord progressions accompanied each melody: highly expected (I-
I6-IV-V-I), slightly unexpected (I-I6-N6-V-I), and highly unexpected (I-I6-IV-V-N6). Subjects’
responses were analyzed for reaction time and accuracy. For musically trained subjects, RT
increased as unexpectedness increased. This relationship was not observed in nonmusicians, who
were slower to respond overall but similar in RT across all chords. Accuracy was significantly
above chance but similar across conditions. A second experiment investigated effects of
harmonic expectation on affect. Subjects rated the pleasantness of the chord progressions on a
four-point scale. On average, more expected chords resulted in higher pleasantness ratings.
Ratings did not vary significantly between musically trained and untrained subjects. Results
suggest that harmonic expectation facilitated melodic perception in musically trained subjects,
whereas nonmusicians were unaffected by harmony. The second experiment showed that all
subjects could distinguish between degrees of harmonic violations while attending holistically to
chord progressions in the pleasantness ratings task.
The above study introduces a new reaction time paradigm to study interactive effects of
different musical elements on psychological expectation. As a follow-up to the above study, we
plan to train subjects to become sensitive towards an artificially constructed set of music-
theoretical rules. Subsequently we plan to obtain pleasantness ratings as well as reaction time
and electrophysiological data in order to assess musically evoked emotional arousal and
expectation in the human brain.
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